Subcellular Localization of ATG2 in WDR45 C52 C>T Mouse Brains — 57a — Ariana Edwards, Brandon Meyerink

Beta-Propeller Protein-Associated Neurodegeneration (BPAN) is a rare and devastating progressive disease with a broad phenotypic display that causes neurological symptoms like tractable seizures, developmental delay, and motor and cognitive decline in adolescents. BPAN is inherited through variations of the WDR45 gene on the X chromosome. Currently, there is no cure for this disease, only symptomatic treatment. While the specific function of the WDR45 protein is unknown, we have determined that its top protein interactor is ATG2 through BioID experiments which agrees with previous literature. ATG2 is an autophagy-associated protein that facilitates lipid transfer between two lipid membranes. Recent publications showed that in HeLa and neuroblastoma cells, WDR45 loss of function leads to mislocalization of ATG2, causing lipid peroxidation and driving cell death via ferroptosis. As BPAN is a principally neurological disease, we wanted to determine the localization of ATG2 in both WT and WDR45 C52 C>T neuronal cultures, which mimics a patient mutation of WDR45. These cultures were used with immunofluorescent imaging to determine colocalization of mitochondrial protein with ATG2. We used subcellular fractionation of cortical tissue collected from WDR45 mutant mice that allowed us to isolate mitochondrial fractions from the tissues, then used western blotting to quantify the amount of ATG2 localizing to these fractions. From this, we did not observe altered ATG2 abundance in the mitochondrial fraction in the absence of WDR45. This finding provides further insight into the function of WDR45 and how it interacts within the scope of BPAN.

Sanford Research
Louis-Jan Pilaz